Cameras cannot easily be used or placed in some locations to take pictures (images) or videos. For example, it is not easy to use or position cameras at certain locations, such as above a tree or pole to take pictures of a skiers doing somersaults.
Even if there is access to such a location, it is likely that only a few people can use the location at a time. In some situations, many people may want to take pictures and/or videos from the same location (e.g., to capture the same view or scene) with different subjects (e.g., skiers) in the pictures. Another situation where many people may want to take pictures of the same view is taking pictures of graduates receiving their diplomas at a graduation.
Subjects, such as skiers, skaters, etc., may want to capture their images while jumping a ram or flipping a somersault. The subjects would have to rely on other people to take pictures for them.